1. Field of the Invention
The present invention relates to a conveyor system for transporting goods with an endless conveyor belt, which is guided over deflection drums in the two end stations and which has support beams oriented transversely to the conveying direction. Conveyor cables are disposed laterally outside the conveyor belt which absorb and carry the loads when goods are conveyed on the conveyor system.
Prior art conveyor systems comprise an endless conveyor belt, guided over deflection rollers on both ends, and support rollers disposed below the upper run. The weight of the conveyor belt comes to rest on the support rollers. The conveyor belt must be sufficiently tension proof so that on the one hand the tensile forces caused by the conveying motion and on the other the tensile forces exerted on it by the weight of the product being conveyed can be absorbed. The tensile loads on the conveyor belt caused by the weight of the goods decrease with a reduction in the distance between the support rollers supporting the upper run of the conveyor belt. Furthermore, in such prior art conveyor systems the support rollers roll relative to the conveyor belt and the conveyor belt also slides over the support rollers. This causes additional high tensile stress on the conveyor belt and the wear on the conveyor belt is further exacerbated.
There exists a need, therefore, in such prior art conveyor systems either to embody the conveyor belt with a very high tensile strength, whereby the support rollers may be spaced farther apart and fewer rollers are necessary over the total length of the conveying apparatus, or to provide more support rollers which are spaced more closely together, whereby the tensile stresses on the conveyor belt caused by the weight of the goods being conveyed are reduced. In the latter scenario, the belt may be formed with a lesser tensile strength. However, a large number of support rollers are required, which increases the construction cost of the system.
There has become known a conveyor system from European patent disclosure 745 545 A1, which has support tracks formed by support cables along which rollers supported on the two ends of the support beams are guided. That prior art conveyor system is disadvantageous because the support rollers are moving parts, which require continual monitoring and maintenance. British patent disclosure GB 1 195 985 A describes a conveyor belt with support beams oriented transversely to the conveying direction. The support beams are coupled to chains by means of protrusions projecting in the direction of the support beams, and acting as supporting and pulling elements. The protrusions are disposed on both sides of the conveyor belt. Conveyor chains, however, are disadvantageous in that they are substantially more expensive to produce than steel cables, and since for a comparable tensile or supporting capacity they have a greater weight than steel cables. Moreover, they are substantially more vulnerable to malfunction than steel cables, because if a single link breaks, many links are rendered nonfunctional.
With regard to the risk of breakage, conveyor cables must be monitored--preferably by magnetic monitoring--so as to ensure early detection of damage and impending breaks.
Swiss patent disclosure CH 544 712 A deals with a conveyor system with conveyor cables which are guided over rollers and with which the conveyor belt is coupled. Coupling is effected by grooves formed in the conveyor belt in which the conveyor cables fit and in which they are positively retained by form-lock. That prior art conveyor system is disadvantageous, however, since because of tensile stresses on the conveyor belt and the conveyor cables, the requisite coupling between the conveyor belt and the conveyor cables is not assured. Once again, therefore, functional problems can result.